// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/renderer_host/pepper/pepper_network_proxy_host.h"

#include "base/bind.h"
#include "content/browser/renderer_host/pepper/browser_ppapi_host_impl.h"
#include "content/browser/renderer_host/pepper/pepper_socket_utils.h"
#include "content/public/browser/browser_context.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/storage_partition.h"
#include "content/public/common/socket_permission_request.h"
#include "net/base/net_errors.h"
#include "net/log/net_log_with_source.h"
#include "net/proxy/proxy_info.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_context_getter.h"
#include "ppapi/c/pp_errors.h"
#include "ppapi/host/dispatch_host_message.h"
#include "ppapi/host/ppapi_host.h"
#include "ppapi/proxy/ppapi_messages.h"

namespace content {

PepperNetworkProxyHost::PepperNetworkProxyHost(BrowserPpapiHostImpl* host,
    PP_Instance instance,
    PP_Resource resource)
    : ResourceHost(host->GetPpapiHost(), instance, resource)
    , proxy_service_(NULL)
    , is_allowed_(false)
    , waiting_for_ui_thread_data_(true)
    , weak_factory_(this)
{
    int render_process_id(0), render_frame_id(0);
    host->GetRenderFrameIDsForInstance(
        instance, &render_process_id, &render_frame_id);
    BrowserThread::PostTaskAndReplyWithResult(
        BrowserThread::UI,
        FROM_HERE,
        base::Bind(&GetUIThreadDataOnUIThread,
            render_process_id,
            render_frame_id,
            host->external_plugin()),
        base::Bind(&PepperNetworkProxyHost::DidGetUIThreadData,
            weak_factory_.GetWeakPtr()));
}

PepperNetworkProxyHost::~PepperNetworkProxyHost()
{
    while (!pending_requests_.empty()) {
        // If the proxy_service_ is NULL, we shouldn't have any outstanding
        // requests.
        DCHECK(proxy_service_);
        net::ProxyService::PacRequest* request = pending_requests_.front();
        proxy_service_->CancelPacRequest(request);
        pending_requests_.pop();
    }
}

PepperNetworkProxyHost::UIThreadData::UIThreadData()
    : is_allowed(false)
{
}

PepperNetworkProxyHost::UIThreadData::UIThreadData(const UIThreadData& other) = default;

PepperNetworkProxyHost::UIThreadData::~UIThreadData() { }

// static
PepperNetworkProxyHost::UIThreadData
PepperNetworkProxyHost::GetUIThreadDataOnUIThread(int render_process_id,
    int render_frame_id,
    bool is_external_plugin)
{
    DCHECK_CURRENTLY_ON(BrowserThread::UI);
    PepperNetworkProxyHost::UIThreadData result;
    RenderProcessHost* rph = RenderProcessHost::FromID(render_process_id);
    if (rph)
        result.context_getter = rph->GetStoragePartition()->GetURLRequestContext();

    SocketPermissionRequest request(
        content::SocketPermissionRequest::RESOLVE_PROXY, std::string(), 0);
    result.is_allowed = pepper_socket_utils::CanUseSocketAPIs(is_external_plugin,
        false /* is_private_api */,
        &request,
        render_process_id,
        render_frame_id);
    return result;
}

void PepperNetworkProxyHost::DidGetUIThreadData(
    const UIThreadData& ui_thread_data)
{
    is_allowed_ = ui_thread_data.is_allowed;
    if (ui_thread_data.context_getter.get() && ui_thread_data.context_getter->GetURLRequestContext()) {
        proxy_service_ = ui_thread_data.context_getter->GetURLRequestContext()->proxy_service();
    }
    waiting_for_ui_thread_data_ = false;
    if (!proxy_service_) {
        DLOG_IF(WARNING, proxy_service_)
            << "Failed to find a ProxyService for Pepper plugin.";
    }
    TryToSendUnsentRequests();
}

int32_t PepperNetworkProxyHost::OnResourceMessageReceived(
    const IPC::Message& msg,
    ppapi::host::HostMessageContext* context)
{
    PPAPI_BEGIN_MESSAGE_MAP(PepperNetworkProxyHost, msg)
    PPAPI_DISPATCH_HOST_RESOURCE_CALL(PpapiHostMsg_NetworkProxy_GetProxyForURL,
        OnMsgGetProxyForURL)
    PPAPI_END_MESSAGE_MAP()
    return PP_ERROR_FAILED;
}

int32_t PepperNetworkProxyHost::OnMsgGetProxyForURL(
    ppapi::host::HostMessageContext* context,
    const std::string& url)
{
    GURL gurl(url);
    if (gurl.is_valid()) {
        UnsentRequest request = { gurl, context->MakeReplyMessageContext() };
        unsent_requests_.push(request);
        TryToSendUnsentRequests();
    } else {
        SendFailureReply(PP_ERROR_BADARGUMENT, context->MakeReplyMessageContext());
    }
    return PP_OK_COMPLETIONPENDING;
}

void PepperNetworkProxyHost::TryToSendUnsentRequests()
{
    if (waiting_for_ui_thread_data_)
        return;

    while (!unsent_requests_.empty()) {
        const UnsentRequest& request = unsent_requests_.front();
        if (!proxy_service_) {
            SendFailureReply(PP_ERROR_FAILED, request.reply_context);
        } else if (!is_allowed_) {
            SendFailureReply(PP_ERROR_NOACCESS, request.reply_context);
        } else {
            // Everything looks valid, so try to resolve the proxy.
            net::ProxyInfo* proxy_info = new net::ProxyInfo;
            net::ProxyService::PacRequest* pending_request = NULL;
            base::Callback<void(int)> callback = base::Bind(&PepperNetworkProxyHost::OnResolveProxyCompleted,
                weak_factory_.GetWeakPtr(),
                request.reply_context,
                base::Owned(proxy_info));
            int result = proxy_service_->ResolveProxy(
                request.url, std::string(), proxy_info, callback, &pending_request,
                NULL, net::NetLogWithSource());
            pending_requests_.push(pending_request);
            // If it was handled synchronously, we must run the callback now;
            // proxy_service_ won't run it for us in this case.
            if (result != net::ERR_IO_PENDING)
                callback.Run(result);
        }
        unsent_requests_.pop();
    }
}

void PepperNetworkProxyHost::OnResolveProxyCompleted(
    ppapi::host::ReplyMessageContext context,
    net::ProxyInfo* proxy_info,
    int result)
{
    pending_requests_.pop();

    if (result != net::OK) {
        // Currently, the only proxy-specific error we could get is
        // MANDATORY_PROXY_CONFIGURATION_FAILED. There's really no action a plugin
        // can take in this case, so there's no need to distinguish it from other
        // failures.
        context.params.set_result(PP_ERROR_FAILED);
    }
    host()->SendReply(context,
        PpapiPluginMsg_NetworkProxy_GetProxyForURLReply(
            proxy_info->ToPacString()));
}

void PepperNetworkProxyHost::SendFailureReply(
    int32_t error,
    ppapi::host::ReplyMessageContext context)
{
    context.params.set_result(error);
    host()->SendReply(
        context, PpapiPluginMsg_NetworkProxy_GetProxyForURLReply(std::string()));
}

} // namespace content
